SPO15 feedback

[TotenDead]

17 часов назад, ASW сказал:

 

 

Nice picture, shame it's far from reality

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[ASW]

19 минут назад, TotenDead сказал:

Nice picture, shame it's far from reality

I'm in the photo on the left, 20 years ago.

[ASW]

6 часов назад, foxbat155 сказал:

You have very small knowledge about Tu-154's navigation system which have nothing to do with Mi-8. Tu-154 had TKS-P2 inertial platform, NVU-BZ navigation computer (analog), DISS-03 doppler navigation radar, GROZA M-154 meteo-navigation radar, KURS-MP2 or KURS-MP70 radio navigation system (RSBN short range, RSDN long range, SP-50M or SO-68 landing system, VOR, DME, ILS) and as a back up automatic radio compas ARK-15M x2. That was typical dead reckoning system for first half of 70's, with correction from radio navigation systems and later in mid 80's with additional correction from sat nav systems. In the same time most of B727 had only ADF, VOR, DME

It is your right to assume that electronics in the USSR were at the level or not worse than Western ones, but the incidents that have occurred with A-50 aircraft in the recent past incline me to trust the DCS developers.

[TotenDead]

15 минут назад, ASW сказал:

I'm in the photo on the left, 20 years ago.

 

 

I suppose I should've sent you this version of 727

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But I was just saying that there were as many knobs and buttons as in 154

Done with off-topic
 

[ASW]

22 минуты назад, TotenDead сказал:

But I was just saying that there were as many knobs and buttons as in 154

Done with off-topic
 

It's not off-topic. I was just reading a Russian forum on this issue and came across an interesting document. I am translating to you what is highlighted in yellow, but in the translation version it sounds softer. than if you correctly convey the meaning in Russian using obscene expressions.)

"When switching on the radar for radiation, it is not possible to use information from the SPO-15LM indicator due to its inaccuracy, and in some cases, its randomness."

It shows errors and chaos occurs on the device!

Edited 8 hours ago by ASW

[Harlikwin]

16 minutes ago, ASW said:

It's not off-topic. I was just reading a Russian forum on this issue and came across an interesting document. I am translating to you what is highlighted in yellow, but in the translation version it sounds softer. than if you correctly convey the meaning in Russian using obscene expressions.)

"When switching on the radar for radiation, it is not possible to use information from the SPO-15LM indicator due to its inaccuracy, and in some cases, its randomness."

It shows errors and chaos occurs on the device!

Yeah, the problem is that thats not how its modeled in the 29 currently. It just doesn't work at all. And the key word in that translation is "may" show incorrect information. Which is very different than it does show that all the time. The most likely cause of the that is blanker going out of synch with the radar as has been discussed previously and this would cause strong spurious signals. But if its working correctly it would not, hence the word "may". This is also a Su-27 doc IIRC. So much stronger peak emissions than the N019, but it probably wouldn't matter too much.

 

 

Edited 7 hours ago by Harlikwin

[AeriaGloria]

23 minutes ago, ASW said:

It's not off-topic. I was just reading a Russian forum on this issue and came across an interesting document. I am translating to you what is highlighted in yellow, but in the translation version it sounds softer. than if you correctly convey the meaning in Russian using obscene expressions.)

"When switching on the radar for radiation, it is not possible to use information from the SPO-15LM indicator due to its inaccuracy, and in some cases, its randomness."

It shows errors and chaos occurs on the device!

This is the one MiG-29 manual it’s mentioned in. 
 

in Su-27 manual it says it is 5-8 signal strength of type X. So you would think if you had a higher priority lock that it would show that instead. 

[ASW]

14 минут назад, Harlikwin сказал:

Yeah, the problem is that thats not how its modeled in the 29 currently. It just doesn't work at all. And the key word in that translation is "may" show incorrect information. Which is very different than it does show that all the time. The most likely cause of the that is blanker going out of synch with the radar as has been discussed previously and this would cause strong spurious signals. But if its working correctly it would not, hence the word "may". This is also a Su-27 doc IIRC. So much stronger peak emissions than the N019, but it probably wouldn't matter too much.

 

 

This is a document. As an aviation engineer I know told me, such documents are written in order to cover your ass with them if necessary. Therefore, the Russian word "maybe" in this document means to me that this thing will most likely not save me and I was warned about it.

[Harlikwin]

5 hours ago, Pavlin_33 said:

What I was thinking is: if there's a trustworthy testimony that SPO was working fine, then it's logical to conclude that in cases where it wasn't there was some sort of hardware issue.

No one knows better how this thing works than people that have used it.

I mean if you ask Yugoslav pilots in '99 about their 29's, where almost none of critical equipment was functional, they would not be a good source for the topic at hand. This however does not mean that Fulcrum is bad, just that it was not maintained.

Well, except some of the accounts of the warnings working while they were running the radar are in fact from Serbian pilots that survived to tell the tale. Supposedly there is an actual GCI recording or transcript of this somewhere.

Honestly I look at this from an occams razor approach.

1. How likely is it the soviets designed a system that purposefully  would be useless with the radar on (given that it worked fine on many other jets)... Pretty low/non existant IMO.

2. How difficult is it to design a blanker circuit that works on these freqs/prfs. Not really that hard on a basic electronics level to do this with 60's/70s circuits, and we have evidence from repair manuals of how out of synch things were fixed. (so its unlikely a design fault, and we have evidence it was supposed to get blanked). 

3. How reliable was the circuit for the blanker... (apparently not very reliable according to several sources)

4.  The mig29 was in service for a short time before the fall of the soviet union. Meaning, it would have early "teething" problems with various equipment likely breaking pretty often (this is a near universal truth with new jets). So, limited spare parts, limited or poorly trained technicians. After the fall of the SU, most client nations certainly ran out of parts/trained techs to work on them in the 90's. 
5. In the 90's or early 2000s, where I assume most of the various SME's were flying the 9.12, aside from the Serbia war, it was peactime. So chances that anyone cared about the RWR being broken or partly inop was probably pretty low. And we have at least one account of it actually working during that war, presumably because someone hoarded enough spare parts to get at least a few RWRs operational, for however briefly they would work (again, this seems very plausible IMO). 

So the simplest explanation for this (occams razor). is that simply most mig29 pilots flew with a broken or partly working or out of synch RWR most of the time. So they are "correct", but they are also likely "wrong" that the system didn't work as designed, because its unlikely to have been designed to "not work", there is no good technical explanation I've heard thus far as to why "it doesn't work". And therefore the simplest explanation is that it was simply broken most of the time on peacetime jets because it doesn't really matter during peacetime. And if the blanker circuit has an MTBF of 10 hours or whatever its gonna be real expensive to keep it running.   

 

7 minutes ago, AeriaGloria said:

This is the one MiG-29 manual it’s mentioned in. 
 

in Su-27 manual it says it is 5-8 signal strength of type X. So you would think if you had a higher priority lock that it would show that instead. 

Thanks for the clarification. thats interesting. Given the mig29 radar is also weaker in terms of peak power it might be even lower in the 29. But so this document is saying it will give spurious readings, not "it will show nothing". 

Also from a processing standpoint if you know your own radars operating frequency, its probably pretty easy to ignore that strong signal at the known operating frequency of the radar. But maybe not if these docs are right. 

[ASW]

I don't know how difficult this is, but there is a suggestion for developers to make an optional SPO. As an INS for the KA-50 III. 

Some people are interested in flying and making corrections, while others have GPS in their car phone.

1. The version as it was conceived in the USSR

2. The version of how it really happened.

This will balance the dogfight multiplayer, which will indicate which version is being used. Those who are interested in flying with the version that was in real life will use it. DCS will kill two birds with one stone in this way, disputes will subside and sales may increase.

Edited 7 hours ago by ASW

[TotenDead]

47 минут назад, ASW сказал:

It's not off-topic. I was just reading a Russian forum on this issue and came across an interesting document. I am translating to you what is highlighted in yellow, but in the translation version it sounds softer. than if you correctly convey the meaning in Russian using obscene expressions.)

 

nullThen you should probably be capable of translating this 

 

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And with this document in mind we can say that the SPO-15 IS CAPABLE of filtering out radar signal from the aircrafts radar. And we can assume that IRL it was either never properly implemented due to, eh, fruits of updated soviet politics and further dissolution of the country, or it was actually made workable, but for the same mentioned reasons there was no way to support the system and it quickly became partially inoperable.

[AeriaGloria]

24 minutes ago, Harlikwin said:

Well, except some of the accounts of the warnings working while they were running the radar are in fact from Serbian pilots that survived to tell the tale. Supposedly there is an actual GCI recording or transcript of this somewhere.

Honestly I look at this from an occams razor approach.

1. How likely is it the soviets designed a system that purposefully  would be useless with the radar on (given that it worked fine on many other jets)... Pretty low/non existant IMO.

2. How difficult is it to design a blanker circuit that works on these freqs/prfs. Not really that hard on a basic electronics level to do this with 60's/70s circuits, and we have evidence from repair manuals of how out of synch things were fixed. (so its unlikely a design fault, and we have evidence it was supposed to get blanked). 

3. How reliable was the circuit for the blanker... (apparently not very reliable according to several sources)

4.  The mig29 was in service for a short time before the fall of the soviet union. Meaning, it would have early "teething" problems with various equipment likely breaking pretty often (this is a near universal truth with new jets). So, limited spare parts, limited or poorly trained technicians. After the fall of the SU, most client nations certainly ran out of parts/trained techs to work on them in the 90's. 
5. In the 90's or early 2000s, where I assume most of the various SME's were flying the 9.12, aside from the Serbia war, it was peactime. So chances that anyone cared about the RWR being broken or partly inop was probably pretty low. And we have at least one account of it actually working during that war, presumably because someone hoarded enough spare parts to get at least a few RWRs operational, for however briefly they would work (again, this seems very plausible IMO). 

So the simplest explanation for this (occams razor). is that simply most mig29 pilots flew with a broken or partly working or out of synch RWR most of the time. So they are "correct", but they are also likely "wrong" that the system didn't work as designed, because its unlikely to have been designed to "not work", there is no good technical explanation I've heard thus far as to why "it doesn't work". And therefore the simplest explanation is that it was simply broken most of the time on peacetime jets because it doesn't really matter during peacetime. And if the blanker circuit has an MTBF of 10 hours or whatever its gonna be real expensive to keep it running.   

 

Thanks for the clarification. thats interesting. Given the mig29 radar is also weaker in terms of peak power it might be even lower in the 29. But so this document is saying it will give spurious readings, not "it will show nothing". 

Also from a processing standpoint if you know your own radars operating frequency, its probably pretty easy to ignore that strong signal at the known operating frequency of the radar. But maybe not if these docs are right. 

I don’t know about peak power, and the N-001 is basically a larger N-019, but average power of both radars is identical. 
 

“Hey it’s ‘Operational validation and testing by MOD to get it approved for service’ day”

MOD: “Why doesn’t the RWR work when the radar is on? Can’t this be fixed??? How does this happen after all this time and money????”

MiG: “uhhhhhhh. I guess we just didn’t think it a priority! Should we fix it for service entry sir?” 
 

MOD: “I mean if you think it’s low priority……. Why not……. It’s only a defensive system!” 

[Harlikwin]

6 minutes ago, ASW said:

I don't know how difficult this is, but there is a suggestion for developers to make an optional SPO. As an INS for the KA-50 III.

1. The version as it was conceived in the USSR

2. The version of how it really happened.

This will balance the dogfight multiplayer, which will indicate which version is being used. Those who are interested in flying with the version that was in real life will use it. DCS will kill two birds with one stone in this way, disputes will subside and sales may increase.

Yeah honestly a tic-box solution of pick your own version to this seems to be the best answer given how contentious and unclear the data is. 

[ASW]

4 минуты назад, TotenDead сказал:

And with this document in mind we can say that the SPO-15 IS CAPABLE of filtering out radar signal from the aircrafts radar. And we can assume that IRL it was either never properly implemented due to, eh, fruits of updated soviet politics and further dissolution of the country, or it was actually made workable, but for the same mentioned reasons there was no way to support the system and it quickly became partially inoperable.

 don't know how difficult this is, but there is a suggestion for developers to make an optional SPO. As an INS for the KA-50 III. 

Some people are interested in flying and making corrections, while others have GPS in their car phone.

1. The version as it was conceived in the USSR

2. The version of how it really happened.

This will balance the dogfight multiplayer, which will indicate which version is being used. Those who are interested in flying with the version that was in real life will use it. DCS will kill two birds with one stone in this way, disputes will subside and sales may increase.

[Harlikwin]

39 minutes ago, AeriaGloria said:

I don’t know about peak power, and the N-001 is basically a larger N-019, but average power of both radars is identical. 
 

“Hey it’s ‘Operational validation and testing by MOD to get it approved for service’ day”

MOD: “Why doesn’t the RWR work when the radar is on? Can’t this be fixed??? How does this happen after all this time and money????”

MiG: “uhhhhhhh. I guess we just didn’t think it a priority! Should we fix it for service entry sir?” 
 

MOD: “I mean if you think it’s low priority……. Why not……. It’s only a defensive system!” 

 

I mean the other half of this, is doctrinally, the soviets were having GCI run encounters so you didn't need SPO if GCI could call a missile launch for you which AFAIK is still very much a thing today. But we have neither some AI GCI to do this for us, and lazur isn't implemented yet either. But keeping it to the SPO, it was one part of a series of systems. And the other part of it is that aside from the mig29/su-27 it seems to have generally worked well on other jets with radars of their own, albeit lower PRF ones in the case of the 23MLD or in the case of the SU-24's ground attack orion that likely worked at MPRF at least, and AFAIK there aren't any comments about the SPO not working with that. 

 

 

[okopanja]

7 hours ago, ASW said:

It's not off-topic. I was just reading a Russian forum on this issue and came across an interesting document. I am translating to you what is highlighted in yellow, but in the translation version it sounds softer. than if you correctly convey the meaning in Russian using obscene expressions.)

"When switching on the radar for radiation, it is not possible to use information from the SPO-15LM indicator due to its inaccuracy, and in some cases, its randomness."

It shows errors and chaos occurs on the device!

I am pretty sure I can by now quote you 3-4 documents of actual technical nature (this is user manual you are quoting) quoting that SPO gets blanked while Radar transmits. These documents and user accounts contradict each other and ED is fully aware of this. 

The devices you discuss now in 2025 were designed in 1970s and 1980s in Soviet Union with what was the technological base available to them. The technological base of the west at that moment was on the one magnitude higher level (we should just take a look at advances in microprocessors during late 70s and early 80s). Designing devices that meet equivalent requirements with weaker tech base did result in number of compromises. 

One of them is MTBF. We can take as example F-15 radar which had 250 hours, while the 29s radar is stated as 50 hours. For SPO-15 stated MTBF is 300 hours. Both Radar and SPO-15 were designed with each other in mind, and contain blanking mechanism which was designed to prevent SPO receiving own radar signals. This is how the devices left design bureau and likely the production facility with instructions to the maintenance crews: replace certain parts every XX number of flight hours. You fail to do one of those things and the combination will not work as designed. Plus a number of issues simply appear during exploitation. Surely you as aviation engineer will not fail to recognize that.

When considering what went wrong, you need also to picture what happens when latest tech arrives to the unit (remember we are still talking 80s here). Both pilots and technical stuff are eager to use latest tech, but have habits and knowledge which is based on the old tech. People used to analogue technology (possibly working on it for 10-30 years) are forced to switch the latest state of the art digital tech. In real world this does not work so great. Add on top that both Soviet Union and e.g. Yugoslavia did face economic, political and military turmoil and you got all the ingredients there for things to go wrong.

I personally took a great interest in SPO topics, going to the great length to find and study technical documentation, and I must say the blanking feature is certainly there. What caused it to fail, I can not tell yet. Not all of the connection and signaling diagrams are available. 

Also notice that video showing SPO-15LM components also shows that the device had a number of wired by-passes in additional to the regular printed circuits. Immediate questions arise:

1. Was this result of production defects, so the additional lines had to be added after a number of boards has been already produced?
2. Was this result of field repairs?
3. Was this result of modifications on the SPO, e.g. to augment it's functionality.

We should also not forget that design was modular and that some sort of modification in "strobe programming" for field modifications was envisioned from the very beginning. We see that both in video and the technical design principles document for SPO. Yet we still do not know how to encode them!

So to complete this "little" rant, instead of quoting user manuals that voice frustration of end users, lets take a trip to the deeper level of actual technical documentation and try to figure out what this device was truly designed to do and how it would have behaved if it was (not) properly maintained.

Edited 46 minutes ago by okopanja

[Yurec.orl]

7 часов назад, ASW сказал:

but the incidents that have occurred with A-50 aircraft in the recent past incline me to trust the DCS developers

What incidents, and how are they related to Mig-29 in DCS?

[Кош]

According to Polish Airforce radar and computer Exploitation manual, and Soviet SPO-15LM service manual for regimental service stations(ТЭЧ), SPO is synced.

It can be out of sync for two reasons: faulty electrical connections in cables, software error in the BTsVM. 

As for 90's manuals stating it's out of sync - it's indeed an ass covering document to cover MOD not functioning properly.

14 минут назад, Yurec.orl сказал:

What incidents, and how are they related to Mig-29 in DCS?

Destruction on the ground by diversion and 1 case of friendly fire over own territory. Judge for yourself how it connects.

Edited 22 minutes ago by Кош